The health status of the oral cavity is in large part influenced by constituents in saliva. The principal function of salivary glands is the production of this complex fluid. To study the mechanisms controlling secretion of salivary components we have utilized both in vitro and in vivo animal preparations. As a probe of secretory events we have primary focused our studies on peturbations of gland functions that occur with normal aging. In particular the role of specific neurotransmitter induced phenomena to secretory events has been investigated. Included are studies of: (1) protein production, processing and secretion from submandibular gland cells in vitro and its relationship to calcium mobilization; (2) water and electrolyte secretion from the parotid gland (K+ and Ca++ fluxes, Alpha-adrenergic and cholinergic responsiveness) in vitro; (3) parasympathetic control of fluid, electrolyte and exocrine protein release in vivo from parotid and submandibular glands; and (4) adrenergic control of intermediary metabolic functions of the parotid gland during secretion.